JPS6261040A - Detecting method for original size in copying machine - Google Patents

Abstract

PURPOSE:To minimize the time loss due to size detection and to shorten the time necessary for obtaining a fist copy by shifting a scan optical system at a maximum scan position side during the luminous energy stabilizing time of an exposure light source with the use of said time and detecting the original size when said system is returned from said maximum position. CONSTITUTION:When an original size detecting mode is set, the 2nd and 3rd mirrors 13 and 14 and an image forming lens 15 are moved and set at a position of an unmagnified m=1 even in a variable power copy mode, and the 1st scanner can be moved at the maximum scan position RP, in which the luminous energy of a halogen lamp 10 is stabilized. Then, the reciprocating movement of the 1st scanner is started, thereby detecting the original size.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a document size detection method in a copying machine.

2. Description of the Related Art Conventionally, some copying machines are designed to detect the size of a document. The effectiveness of size detection can be roughly divided into automatic paper selection (APS) and automatic magnification selection (AMS).
There are two. APS is a function that automatically selects and feeds transfer paper of the same size as the original size determined by original size detection from a multi-stage cassette, and copies it at the same size. The latter AMS is a function that calculates a magnification based on the ratio of a preselected transfer paper size and an original size, and obtains a copy with a magnification corresponding to the transfer paper.

Here, as a conventional document size detection method, there is a method in which the document is illuminated with an exposure lamp and the size of the document is detected based on the light reflected from the document. Here, when detecting M document noise, it is necessary that the light intensity of the FF light lamp is stable.However, if the exposure lamp is a halogen lamp, for example, after one light is turned on, the light intensity of the FF light lamp must be stable. Usually takes 500-800 ms.

Therefore, in Juto, after the light intensity of the exposure lamp stabilizes, the scanning optical system is started (-), the document size is detected during forward movement, and after the detection, the scanning optical system is returned to the home position. , from here the original exposure run for image creation
¥: I try to do it. As a result.

When detecting the original size, it takes a long time to obtain the first copy.

That is, the waiting time after pressing the print button is long.

-',,'ji, Set the normal standby position of the scanning optical system to the opposite position from the home position for starting exposure, and perform document size detection when returning the optical system to the 11 position. , this Ho 11 position or 1゛)
There is also a system in which the original original exposure is performed when the original document is returned. However, even with this method, since the scanning optical system is moved toward the hole position after the light amount of the exposure lamp has stabilized, the first copy takes an hour longer. and.

When copying, for example, a book-like original without requiring original size detection, the original pressure plate is opened, so n3111. Lamp light (movement)
1 of the operator, and it is difficult for the operator to understand where the copy is being made, which may result in copy errors.

Purpose The present invention has been made in view of the above points, and an object of the present invention is to provide a method for detecting the size of a document in a copying machine, which can shorten the time required to detect the size of the document and thereby shorten the time required to obtain a first copy. purpose.

Structure In order to achieve the above object, the present invention includes a scanning optical system including an exposure light source for exposing and scanning a document, a control means for controlling the reciprocating movement of the scanning optical system, a four-color document pressure plate, and a device for exposing and scanning a document. A copying machine equipped with an original size detection means for determining the original size from the difference in reflected light from the original pressing plate,
In the document size detection mode, the @ arrangement light light source is turned on, and the scanning optical system is moved forward to the maximum scanning position in a time less than the time required for photoelectric stabilization, and the scanning optical system is moved from this maximum scanning position. Before when returning! The present invention is characterized in that the original size is detected by operating the 8 original size detection stage f.

An embodiment of the present invention will be described below based on the drawings. First, the configuration of a copying machine will be explained with reference to FIG. A contact glass 2 is provided on the top of the copying machine main body 1, and an automatic document feeder (ADF) 3 is provided on the contact glass 2. This ADF3 has an M draft pressure plate (not shown)
and can be selectively attached to this contact glass 2.

The originals 5 stacked on the original platen 4 are fed one by one by a paper feeder 6, are conveyed over the contact glass 2 by a conveyor belt 7, and are stopped at a predetermined position.
After copying, the conveyor belt 7 is driven again to discharge the original 5 onto the original tray 8.

On the other hand, a scanning optical system 9 is provided below the contact glass 2. This scanning optical system 9 is connected to a contact glass 2.
A halogen lamp 10 as an exposure light source for exposing and illuminating the original 5 of No. 42, first to third mirrors 12, 13, and 14 that receive reflected light from the original 5 and form an image on the photoreceptor 11, and an imaging lens 15. It consists of a fourth mirror 1G. Here, the halogen lamp 10 and the first mirror 12 are used as a first scanner and are driven by a scanner motor 17, and when copying, the home position HP (original set on the contact glass 2 in the original pressing plate mode) - reference position) to the maximum scanning position (return position) RP
It is set to move forward to the maximum scanning position ftRP, and then move back to the home position HP again from this maximum scanning position ftRP. The second and third mirrors 13 and 14 are used as second scanners,
It is set to move in the same direction at 1/2 the speed of the first scanner. In addition, this embodiment has a variable magnification function, and the 2nd and 3rd mirrors 13 and 14 are used during variable magnification copying.
is moved to a predetermined position according to the magnification by a mirror motor 18, and the imaging lens 15 is also set to be moved to a predetermined position by a lens motor 19.

Further, a document size detection means 20 is mounted on the first scanner. This document size detection means 20 includes an optical fiber 21 whose tip end is mounted on the first scanner so that reflected light when the document 5@ is illuminated by the halogen lamp 10 is incident thereon.

A photodiode 22 is provided at a fixed portion within the main body of the apparatus so as to face the other end of the optical fiber 21. Here, such document size detection means 2
Detection of the original size by 0 is carried out based on the difference in appearance between the reflected light from the original 5 and the reflected light from the conveyor belt 7, which functions as an original pressure plate. Therefore, the background of most originals 5 is white. 44, and the conveyor bell l-7 is colored yellow to create a difference in the reflected sight (in this embodiment, ADF3 is used).

This 80F3 and the selectable document pressure plate are also connected to the conveyor belt 7.
The spectral reflectance of the spectral reflectance is approximately the same as that of the spectral reflectance of the spectral reflectance. The reason for coloring in yellowish color is to utilize the spectral sensitivity characteristics of the photoreceptor 11 shown in FIG. That is, the sensitivity of the photoreceptor 11 is low for yellowish short wavelength light, so it is difficult to capture it as an image, and the light diode 2 used in this example
This is because the sensitivity of No. 2 is on the shorter wavelength side, and the sensitivity is relatively high for white colors and low for yellow colors. By the way,! The half-value width of the spectral sensitivity of each of the three-light body 11° photodiode 22 is approximately 490 to 6
20 nm, 420-470 nm.

Note that the structure surrounding photoreceptor 1 is well-known, and although not described in detail, various steps such as charging, exposure, development, transfer, cleaning, and charge removal are repeated in synchronization with the scanning operation of the scanning optical system 9. The single paper processing system is equipped with a multi-stage transfer paper cassette 23, which is set so that various sizes of transfer paper 24 can be selected.The fed transfer paper 24 is synchronized with the image on the photoreceptor 11. and transported to the transfer section.

After that, it is fixed and discharged.

Next, a block diagram of the control system is shown in FIG.

Basically, input/output processing is executed by a CPU (microcomputer) 25 via an I10 port 26 for load and an I/'0 port 27 for input.

The optical signal for detecting the document size from the optical fiber 21 is input to the optical diode 22 .

A of the CPU 25 is amplified by the OP amplifier 28.29.
In this embodiment, the document size is detected from the scanner operation and this A/D input value using a built-in timer.
is the contact glass 2 based on the t1 position HP.
With the document 5 set above, the first scanner of the scanning optical system 9 moves back to the left at the maximum scanning position RP, and calculates the timer value at the time when the right edge of the document 5 is detected.
is set to determine the length of the . Further, the scanner motor 17, the mirror motor 18. Lens motor 9
is controlled by the CPU 25 via the DC motor controller 30 to change the speed and drive the scanner motor 17 in forward and reverse directions, and to drive the mirror motor 18 and lens motor 9 in forward and reverse directions. Further, the halogen lamp 1.0 is subjected to AC phase control of voltage applied from a stabilized power source 32 via a D/Δ converter 31.

That is, this phase control is performed according to the baldness adjustment state of the operating section (not shown), and the lighting state of the halogen lamp 10 is controlled. Motoo.

When detecting the document size, the amount of light incident on the photodiode 22 changes as shown in FIG. 6 depending on the amount of light from the halogen lamp O, so that the phase is controlled to be constant so that detection is always performed in a constant scene.

Control of the copying operation in the second embodiment will now be explained with reference to the timing chart of FIG. 3 and the flowchart of FIG. 4. In addition, the operation section has size detection mode, variable magnification mode, and ADF mode.

A switch is provided for selecting and inputting various modes such as APS mode and 8MS mode.

First, it is checked whether or not the size detection mode is set, and if the size detection mode is not set, the print signal is output.
It will be in a state of waiting for N. Then, when the print button is pressed and the print signal is turned ON, it is checked again whether or not the document size detection mode is set. In this case, since the mode is not the original size detection mode, a normal copy routine is executed.

In this normal copying routine, the halogen lamp 10 is set by the operator, the phase angle of the stabilized power source 32 is set corresponding to the image density notch, and the halogen lamp 10 is turned on. Then, the drive motor for driving the photoreceptor 11 and the like is also turned on. The time required for the halogen lamp 10 to stabilize its light intensity after being turned on varies somewhat depending on the operating voltage, but in this embodiment, it takes about 600 rns. Then, after turning on the halogen lamp 10.

After GOOms have elapsed, the routine shifts to execution of the normal copy routine. That is, forward movement of the scanner motor 17 for exposure scanning of the original 5 is started. This scanner motor 17
The driving speed of is the third speed.

This speed changes depending on the set magnification of the operation sound. As a result, the first scanner of the scanning optical system 9 moves forward from the home position HP toward the maximum scanning position 11RP to expose and scan the document surface. A copy processing routine is then executed in parallel.

This copy processing routine controls the equipment around the photoreceptor 11 such as charging, development, and transfer, and feeds the transfer paper 24.

The controls for registration alignment, paper ejection, etc. are well known, so their explanation will be omitted. After that, when the first scanner performs exposure scanning for a length corresponding to the magnification and paper size, the preset scanner travel counters match, so at that point the scanner motor 17 is reversed to start backward movement. . The speed of the scanner motor 17 during this backward movement is a preset fourth speed, and is driven at high speed to increase the copying speed. As a result, the first scanner returns to the Ho 15 position HP at high speed.

Here, it is checked whether the number of copies per copy matches the preset number of copies for repeat copying, and if they do not match, the first scanner returns to the 11th position HP depending on whether the HP sensor is turned on. To check. Then, upon returning to the home position HP, the scanner motor 17 is turned off. Thereafter, the copy routine is executed repeatedly in the same manner. If the number of copies is equal to the number of copies set, it is checked whether the ADF mode is selected. If it is not the ADF mode, wait for the HP sensor to turn on, and when the first scanner returns to the home position HP, turn off the scanner motor 7 and turn off the halogen lamp 10. Then, post-copy processing such as cleaning the photoreceptor 11 and discharging the transfer paper 24 is executed. Finally, turn off the drive motor.
F and waits for the next print command. On the other hand, in Go〇F mode, it is checked whether there is a primary original 5, and if there is still an original 5, after the previous original 5 is ejected, the copying operation is performed for the following original 5 in the same way, and the original 5
If it runs out, the copy post-processing etc. will be executed in the same way.

The case where the document size detection mode is set will now be described. When this mode is selected, it is first checked whether it is the variable magnification mode.

When in the variable magnification mode, the second and third mirrors 13 and 14 and the imaging lens 15 are set to the same magnification position. This point will be explained in detail. In general, in the case of variable magnification copying, as shown in Figure 1, the 2nd and 3rd mirrors 13, 14 and the imaging lens 15 are located at various variable magnification positions, and by changing the optical path length, copies with the desired magnification can be made. is configured so that it can be obtained.

In FIG. 1, the states indicated by 13a, 14a, and 15a are the same magnification m=1 position, and 13b, 14b, and 15b
The state shown by is the position where the reduction ratio is '4Km=0.5.

The state shown by 3, 3e, 14c, l5e is the magnification magnification m=1.41. Therefore, at the time of enlarging copying, the position of rn=1.41 is indicated by the second and third mirrors 13e and 14c and the imaging lens 15c. Therefore,
When attempting to move the first scanner of the scanning optical system 9 to the maximum scanning position RP, the third mirror 14c and the imaging lens 15c collide due to the layout, and the first scanner is not moved to the starting position for document size detection. A certain maximum scanning position RP
Therefore, the second and third mirrors 13 and 14 and the imaging lens 15 are set to be moved to the same magnification m = 1 h1 even in the variable magnification copy mode, and the first scanner can be moved to the maximum scanning position RP. Also, as mentioned above, the effectiveness of document size detection is A'PS and AMS, but when these functions are taken into account, when detecting the document size, it is necessary to set the document size to the original size beforehand. This can be said to be more advantageous in terms of control and operation. For this reason, in this embodiment, in the 1M document size detection mode, even in the variable magnification mode, the second and third mirrors 13 . ．．
14 and the imaging lens] 5 are set at the same magnification position.

After this, when the print button is pressed and the print is turned on,
Since this is the document size detection mode, in this case, the halogen lamp 10 is controlled to be lit in four notches. This is about 65 V rm in order to always light the halogen lamp 10 with a constant light intensity during size detection as described above.
The light is turned on by pressing s. At the same time, the drive motor is also turned on.
to rotate the photoreceptor 11. This is because the light from the halogen lamp 10 also illuminates the photoconductor 71, so rotating the photoconductor 11 prevents partial optical fatigue of the photoconductor 11. If it is not the mode, forward movement of the scanner motor 17 is started to move the first scanner from the home position IIP to the maximum scanning position [RP. At this time.

Scanner motor 17 is driven at a first speed.

The reason why the first scanner is moved to the maximum scanning position lRP in this way is that it takes approximately 600 rns for the light intensity of the lit halogen lamp to stabilize.
The first scanner reaches its maximum scanning position within this time! ] speed is set so as to reach RP. In addition, in the SDF mode, the document transport motor is turned on to carry out document transport, and in order to stop the document 5 at a predetermined position on the contact glass 2, the document feed counter also starts! − to make.

At this time, the speed of the document transport motor is the same as that of the first scanner of the first scanner.
It is set faster than the speed, and the first scanner is at its maximum scanning position! i! Before the RP sensor, which detects that the RP has been reached, is turned on, the document feed counter reaches a predetermined value and the document conveyance motor is turned off. Here, to give an example, the distance between the first scanner and document transport is approximately 480 mm, the first speed is approximately 800 m/s, and the fi document transport speed is approximately 1
000 m/s, the traveling time of the first scanner is (EOOrns), and the transport time of M document 5 is 48
It becomes 0ry+s.

In this way, the first scanner has a maximum scanning position of 11RP.
In the state where it has moved to , the amount of light from the halogen lamp 10 is stable. Therefore, this most dog race N rank WRP
The document size detection operation is executed by starting the backward movement of the first scanner. Therefore, the size counter starts 1. Start detecting the document size. At this time, the faster the backward movement speed of the first scanner is, the shorter the first copy time can be, but if it is too fast, the size detection error will increase as shown in Figure 7, which shows the relationship between the backward movement speed and the detection error. As the speed increases, the accuracy deteriorates, so in this example, the second speed at this time is set to 480 m+/s.
is set to suppress the detection error to 3 m or less (However, if the detection accuracy is not bad, this second speed may be increased to about 1000++ s/s)
When the first scanner moves back, the document 5 is set based on the home position HP, so the reflected light from the conveyor belt 7 is initially guided to the photodiode 22 by the optical fiber 21. As the movement progresses and the amount of reflected light 5 changes, so that the photodiode 22 receives the reflected light from the edge of the original 5, a state in which an original signal is present is entered. This causes the size counter to stop and calculate backwards from the count value of this size counter.
! In this embodiment, this size counter has a timer configuration, and the size counter is determined from the RP sensor position to i(
The speed up to P sensor position 4 is 480++s+, and the detection speed (second speed) is 480 am/s, so the first scanner moves from the maximum scanning position RP to Ho 11 position I.
(It will take loooms time to move to P. Therefore, for example, if the content of the size counter (timer) is T = 380ms (see Figure 3), the size of document 5 at this time is 1000- 380 = 620 (m
q), 620m5xi1.80 wa/s
= 297, 6 circles. This is A.1 vertical (2
97m) It is determined that it is the document 5 to be sent. And I
When the P sensor is turned on and it is detected that the first scanner has returned to the Baum position HP, the scanner motor 17 is turned off.

Next, check whether the size has been recognized in such R draft size detection. If the size is not recognized, size unknown is displayed, the halogen lamp 1o and the drive motor are turned off, and the next command is waited. ,S,ism F
If ll is set, it is determined whether the mode is APS mode or AMS mode. In APS mode, transfer paper 24 of the same size as the recognized original 5 is transferred to the printer.
- Check that the transfer paper 2 is
4, this transfer paper 24 is automatically selected and fed, and the process proceeds to the next step. If there is no transfer paper 24 of this size, the transfer paper check display is turned on and the halogen lamp 10 and drive motor are turned on. OFF and waits for the next command. On the other hand, in the AMS mode, the magnification is calculated from the ratio between the recognized original size and the preselected size of the transfer paper 24. For example, if the original is A3 size and the transfer paper 24 is A4 size, the magnification will be 0.71. The second and third mirrors 13 and 14 and the imaging lens 15 are moved and set from the same magnification position to a predetermined position according to the magnification calculated in this way. is calculated according to the magnification.

Proceed to next step. Note that since such APS mode and AMS mode processing is well known, details thereof will be omitted.

In this way, when the processing for the ASP mode or A M or S mode is completed, the notch of the halogen lamp 10 is deflected to the notch specified by the operator. Then, the scanner motor 17 is moved forward at a predetermined third speed, and the first
The scanner starts exposure scanning from the Ho 11 position HP. After that, the copy routine is executed in the same way as the normal copy routine, and the series of copy processing is completed.

Figure 3 shows a timing monitor that supports this type of processing.
This indicates -@ of 1-, and in this case, the original detection mode is selected and the repeat copying mode (the number of sheets is 1) is selected.
The case of 1 sheet is shown.

In this way, by using the document size detection method of the two embodiments,
For example, although it takes time for the light intensity of the halogen lamp 10 to stabilize, the scanner of the scanning optical system 9 is moved from the ho 11 position HP to the maximum scanning position tilRP within this time, and the maximum scanning position RP is The document size is detected during the return movement from 11, and when the document returns to position H1), the original document 5 is exposed and scanned to obtain a copy.
Even if the document size is detected, the time required to obtain a first copy can be shortened without being affected by the stabilization time of the halogen lamp 10. or.

If document size detection is not required, the operation for document size detection is not performed and the ``Ho!'' message is displayed. , the normal n9 scans from position IIP are sufficient, so the time required to obtain the first copy is short.

Furthermore, even in the variable magnification mode, when detecting the document size, the second and third mirrors 13.14 and imaging lens j5 for variable magnification are not moved to the variable magnification position, but are moved to the same magnification position. As a result, the scanning optical system 9 can perform full scanning and can detect any size of the document 5. As a result, A
PS function and AMS function can be performed without restrictions.

In particular, since the AMS function is a function that automatically sets the magnification based on the original size and the selected transfer paper size, it is reasonable to return to the -11 normal magnification state as in this embodiment.

Effects The present invention utilizes the sight stabilization time of the front light source in a double series to move the scanning optical system to the maximum scanning position within that time, and then adjusts the document size when returning from this position. Since the size is detected, the time required to obtain a first copy can be shortened by minimizing the time required to make a tie by size detection.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is a schematic side view, Fig. 2 is a block diagram, Fig. 3 is a timing chart, Fig. 4 is a flowchart, and Fig. 5 is a diagram of spectral sensitivity. The characteristic diagrams shown in FIG. 6 are the detection speed-detection error Xmi characteristic diagram, and FIG. 7 is the characteristic diagram of the lamp voltage-detection voltage characteristic. 5. Original, 7. Convey belt (original pressure plate), 9. Scanning optical system, 10. Halogen lamp (n-point light source). 20・-・Applicant for document size detection method Ricoh Co., Ltd. −□・■Sumiyoshi Osamu Akira Aiki 1
(,j→ls...1 Daidan 37 times,,:% 3 skill

Claims (1)

[Claims] A scanning optical system including an exposure light source that exposes and scans the original, a control means that controls the reciprocation of this scanning optical system, a colored original pressure plate, and a document size determined from the difference in the amount of light reflected from the original and the original pressure plate. In the copying machine, the exposure light source is turned on when in the document size detection mode, and the scanning optical system is moved forward to the maximum scanning position in a time less than the time required for stabilizing the light amount;
A method for detecting a document size in a copying machine, characterized in that the document size is detected by operating the document size detecting means during the backward movement of the scanning optical system from the maximum scanning position.